Process for development of two component diazotype photosensitive materials

ABSTRACT

A process for development of two-component diazotype photosensitive materials comprising exposing image-wise to light a photosensitive material having a two-component diazotype photosensitive layer comprising a photosensitive diazonium salt, a coupler capable of coupling with said diazonium salt and an acidic stabilizer, applying a small amount of an activating liquor to the photosensitive layer of the exposed photosensitive material and thereafter heating the activating liquor-applied photosensitive material according to need, said activating liquor being a solution or dispersion of a carboxylic acid salt selected from the group consisting of alkali metal carboxylates, alkaline earth metal carboxylates and mixtures thereof.

[4 June 28, 1974 PROCESS FOR DEVELOPMENT OF TWO-COMPONENT DIAZOTYPE PHOTOSENSITIVE MATERIALS [75] Inventors: Kouzi Nihyakumen; Taizo Yokoyama; Yasutoki Kamezawa; Tatsuo Aizawa, all of Osaka, Japan [73] Assignee: Mita Industrial Company, Ltd.,

Osaka, Japan [22] Filed: July 25, 1972 [21] Appl. No. 275,071

[30] Foreign Application Priority Data July 31,1971 Japan ..46-57159 [521 U.S. Cl. 96/49, 96/91 R [51] Int. Cl G03c 5/34 [58] Field of Search 96/91 R, 75, 49; 250/65 T; 117/367, 36.8, 36.9

[56] References Cited UNITED STATES PATENTS 2,298,444 10/1942 Weissberger et al.... 96/91 R 2,807,545 9/1957 Frederick 1 96/75 3,301,679 1/1967 Halperin et a1. 96/49 X 3,326,686 6/1967 Randall et a1 96/49 X 3,389,996 6/1968 Welch 96/49 X 3,446,620 5/1969 Parker 96/49 3,529,964 9/1970 Kienast et a1. 96/49 X 3,615,485 10/1971 Islam at al. 96/49 3,615,574 10/1971 lwaoka et a1. 96/49 3,650,750 3/1972 lwata et al. 96/49 FOREIGN PATENTS OR APPLICATIONS 1,127,237 9/1968 Great Britain 96/75 647,069 4/1964 Belgium 96/49 1,041,022 9/1966 Great Britain 96/75 1,230,602 5/1971 Great Britain 96/49 OTHER PUBLICATIONS Abstracts of PS & E Literature, Vol. IV, No. 1, l/1965, Abstract No. 245/65 P (Yamamoto, Jap. 39-814l, 5/1964).

Abstracts of PS & E Literature, Vol. 9, No. 4, 4/1970, Abstract No. 1198/70 P (Oita et al., .lap. 4427,554, 11/1969).

Dietzgen, .1. E.; Reproductions Review, 2/1962, pp. 14,15,22 & 26.

Primary Examiner-Charles L. Bowers, Jr. Attorney, Agent, or Firm-Sherman & Shalloway 5 7] ABSTRACT A process for development of two-component diazotype photosensitive materials comprising exposing image-wise to light a photosensitive material having a two-component diazotype photosensitive layer comprising a photosensitive diazonium salt, a coupler capable of coupling with said diazonium salt and an acidic stabilizer, applying a small amount of an activating liquor to the photosensitive layer of the exposedphotosensitive material and thereafter heating the activating liquor-applied photosensitive material according to need, said activating; liquor being a solution or dispersion of a carboxylic acid salt selected from the group consisting of alkali metal carboxylates, alkaline earth metal carboxylates and mixtures thereof.

6 Claims, No Drawings PROCESS FOR DEVELOPMENT OF TWO-COMPONENT DIAZOTYPE PHOTOSENSITIVE MATERIALS said diazonium salt and an acidic stabilizer, applying a small amount of an activiating liquid to the photosensitive layer of the exposed photosensitive material and thereafter heating the activating liquor-applied photosensitive material according to need, said activating liquid being a solution or dispersion of acarboxylic acid salt selected from the group consisting of alkali metal carboxylates, alkaline earth metal carboxylates and mixtures thereof. A so-called dry development method using a gaseous mixture of ammonia and vapor has been broadly used in diazotype reproduction employing a two-component diazotype photosensitive material having a photosensitive layer comprising a photosensitive diazonium salt, a coupler and an acidic stabilizer. In this dry development method, since the contact of a gaseous mixture of ammonia and vapor acting as a developer with the photosensitive layer is a contact between the gas phase and the solid phase, it is necessary to supply the gaseous mixture in an amount such that the amount of ammonia is such greater than the amount required for coupling the coupler with the diazonium salt. As a result, excessive ammonia is discharged from the developing device and its nasty smell causes trouble.

As means for overcoming the above disadvantage of the dry development method, Japanese Patent Publication No. 39-8 141/64 or No. 45235 /70 has proposed a process comprising applying a small amount of an activating liquid comprising an organic amine such as mono, diand tri-ethanolamines to an light-exposed two-component diazotype photosensitive layer, and developing the photosensitive layer by or without heating.

This development method is advantageous in that the development can be accomplished, as in the dry development method, without substantial wetting of the diazotype photosensitive layer. However, this method has a fatal defect in the point that an organic amine which is highly irritative to skins and mucous membranes and which is readily absorbed in human bodies to give harmful effects thereto must be employed. For instance, ethanolamines, which are amines giving the least nasty smell among organic amines, are considered to give high irritation to skins and mucous membranes and exhibit high absorption in human bodies when they are heated. Therefore, according to The Food and Drug Administration of U.S.A., it is stipulated that in ethanolamines the tolerance should be 3 ppm or less. However, in the above known method comprising application of ethanolamines it is practically very difficult to control the ethanolamine concentration in the environment to less than 3 ppm during the development treatment.

In case a two-component diazotype photosensitive material is developed according to a so-called wet development method employing an aqueous solution of a non-volatile inorganic alkali, the above-mentioned defects can be overcome, but a copy sheet is obtained in the wet state, which results in handling inconveniences. Furthermore, this wet development method is defective in that contrast in the copied image is low and the remaining coupler is discolored by the alkali left on the whole surface of the copy sheet.

As described above, in all of known methods for de' veloping two-component diazotype photosensitive materials the development is conducted with use of an aqueous solution containing a free organic amine or inorganic alkali or a salt forming a free amine or alkali under thermal decomposition. In short, it has been common in the art that the development of twocomponent diazotype photosensitive materials can be effected only in the presence of an organic amine or inorganic alkali.

We have now found to our surprise that when a solution or dispersion of an alkali metal salt or alkaline earth metal salt of a carboxylic acid is applied to a lightexposed two-component diazotype photosensitive material, copied images of high distinction and contrast can be obtained without the above-mentioned disadvantages and defects of the conventional techniques. The alkali metal salt or alkaline earth metal salt to be contained in the activating liquor to be used in this invention is a neutral salt (normal salt) and it is relatively stable at high temperatures, and in this point the activating liquid of this invention can be clearly distinguished from conventional aqueous solutions of organic amines or inorganic alkalis. Further, the mecha- I nism of development by the activating liquor of this invention is quite different from the development mechanism in the conventional development methods.

This invention will now be illustrated in detail.

Any of two-component diazotype photosensitive materials having a photosensitive layer comprising a photosensitive diazonium salt and a coupler capable of coupling with the diazonium salt may optionally be used in this invention. Such photosensitive materials are readily commercially available as dry diazotype photosensitive papers.

In general, the photosensitive layer of such twocomponent diazotype photosensitive material comprises as essential ingredients a light-decomposing diazonium salt, a coupler capable of coupling with said diazonium salt and an acidic stabilizer.

As the light-decomposing diazonium salt, any of diazonium salts which decompose under irradiation and are capable of coupling with a coupler under the developing conditions adopted may be used in the process of this invention. Typical instances of such diazonium salts are as follows:

Diazonium salts of N,N-disubstituted compounds of para-phenylene diamine expressed by the following general formula:

wherein X stands for an anion such as a halogen ion, a sulfuric ion or a fluoroboric ion, R and R which may be the same or different, designate an alkyl group which may be substituted by a halogen atom or a hydroxyl or amino group, and Z and Y are substituents known in the art of dyestuffs as substituents on the benzene nucleus, e.g., hydrogen, halogens, alkyl groups and alkoxy groups. Specific examples of compounds of this type are as follows:

4-Diazo-N,N-dimethylanilin (referred to simply as MA salt) 4-Diazo-N,N-diethylaniline (referred to simply as EA salt") 4-Diazo-N-ethyl-NB-hydroxyethylaniline (referred to simply as EH salt)- 4-Diazo-N,Nbis-B-hydroxyethylaniline 4-Diazo-NmethylN-B-hydroxyethylaniline 4DiazoNethyl-NB-hydroxypropylaniline Other diazonium salts of para-phenylene di-amines N-monoor N,N-di-substituted alkyl or hydroxyl-alkyl groups, such as 4-diazo-N-ethyl-N-(B-diethylamino)- ethylaniline, 4-diazo-2-chloro-N,N-diethylaniline, 4- diazo-2-methyl-N,N-diethylaniline, 4-diazo-2-iodo- N,N-diethylaniline, 4diazo-N-ethyl-N-benzylaniline and 4diazo-N-methyl-N-benzylaniline (referred to simply as methylbenzyl) Diazonium salts of the aminohydroquinone ether type expressed by the following general formula wherein R, R and R which may be the same or different, stand for an optionally substituted alkyl or aryl group, and X is as defined above.

Specific examples of compounds of this type are as follows:

4-Diazo-2,5-dibutoxy-N,N-diethylaniline 4-Diazo-2,5-diethoxy-N-benzoylaniline (referred to simply as T-BB salt) 4-Diazo-2,5diethoxy-N-ethylN-benzoylaniline 4-Diazo-2,5dibenzyloxy-N-benzoylaniline 4-Diazo-2-chloro-5-methoxy-N-benzoylaniline 4-Diazo-2,5diethoxyN-benzoylmethylaniline Other 4-diazo-2,S-dihydroxyalkyl (or dihydroxyaryl)-N-alkyl (or aryl) compounds and derivatives thereof.

Diazonium salts of the aminodiphenyl or aminodiphenylamine type expressed by the following general formula X N -R-AR or X' N R- A--R"N X' wherein R and R which may be the same or different, stand for an optionally substituted aryl group, especially a phenyl group, X is as defined above, and R-AR group stands for a diarylamino group (A NH-), a diphenyl group (A direct bond), a diphenyloxide group (A O), a diarylmethane group (A -CH a stilbene group (A CH=CH) or a diarylsulfide group (A -S-).

Specific examples of compounds of this type are as follows:

Para-diazodiphenylamine 4-Diazo-2,5,4-triethoxydiphenylamine 4-Diazo-2,5,4-triethoxydiphenyl 4,4 -Bis-diazo-2,2 ,5 ,5 '-tetrahydroxydiphenylmethane Bis-diazo-3 ,3 dichloro-S ,5 '-dimethoxybenzidine 4-Diazo-2,5dimethoxyphenylethylsulfide 4-Diazo-2,5-diethoxy-4-methyldiphenylsulfide Diazonium salts of the heterocyclic amine type expressed by the following general formula wherein X, Y and Z are as defined above, and B stands for O (morpholine type), -S- (thiomorpholine type), CH (phenylpiperidine type) or a direct bond (phenylpyrolidine type).

Specific examples of compounds of this type are as follows:

4-Diazo-2,S-dibutoxy-Nphenylmorpholine 4-Diazo-2,5-diethoxy-N-phenylmorpholine 4-Diazo-2methoxy-N-thiomorpholine 4-Diazo-N-phenylpiperidine 4Diazo-N-phenylpyrolidine 4-Diazo-2,5di-n-butoxyNphenylpiperidine Other 4-diazo-Nphenyl-heterocyclic amine derivatives Diazonium salts of N,N-substituted ortho-phenylenediamines and diazonium salts of ortho-aminophenols. Specific examples of compounds of this type are as follows:

2Diazo-4-methylmercapto-N,N-dimethylaniline 2-Diazo-5-benzoylamino-N,N-dimethylaniline Z-Diazo-lnaphthol-S-sulfonic acid The above-mentioned diazo compounds are used in the form of relatively stable diazonium salts, such as sulfates or hydrochlorides. They may also be used in the form of double salts with zinc chloride, tin chloride, aluminum sulfate or the like. They may also be used in the form of diazotates stabilized by aryl sulfonates (diazonium salts of aromatic sulfonic acids) or diazosulfonates (diazonium salts of sulfonic acid acids or their alkali metal salts). These diazonium salts may be used singly, or mixtures of two or more of them may also be used.

As the coupler to be contained in the diazotype photosensitive material, any of couples capable of coupling with a diazonium salt such as exemplified above under development conditions adopted in this invention may be used. For instance, phenol derivatives, naphthol derivatives and active methylene group-containing compounds are used. Specific examples of such couplers are as follows:

Phenol derivatives such as pyrocatechol, resorcine, phloraglucinal, pyrogallol, resorcine monoglycol ether, meta-aminophenol, para-aminophenol, diethylaminophenol, 2,5,6-trimethylphenol, 2- hydroxymethylphenol, B-(Z-hydroxyphenyl)-propionic acid, Z-(w-phenylaminomethyl)-phenol, B-(4-methyl- 2-hydrophenol)-glutaric acid, 2,5dimethyl-6-(N- dimethylaminomethyl)-phenol, the l,3-dimethyl ether of pyrogallol, a-resorcyclic acid ethanolamine, N-lauryl-para-aminophenol, B-resorcylic acid ethanolamine, N-acyl-meta-aminophenol, meta-hydroxyacetoanilide, ortho-Nhydroxydiphenol-monoguanidine, para-N- hydroxydiphenyl-bi-guanidine, morpholinomethylphenol, morpholinomethylphenol, methylresorcinol 3 ,3 ',5 -trihydroxydiphenyl, 3,3,5,5'-tetrahydroxydiphenyl, 2,2',4,4'-tetrahydroxydiphenyl, 2,4,4-trihydroxydiphenyl-2'-sulfonic acid, 2,4,6,3',5'-pentahydroxydiphenyl, and 2,2,4,4'-tetrahydroxydiphenyl.

Hydroxynaphthalene derivatives such as 2,3-dihydroxynaphthalene, B-naphthol, a-naphthol, l,6 dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,3- dihydroxynaphthalene-6-sulfonic acid, 2-naphthol-3,6- disulfonic acid, 2,7-dihydroxynaphthalene-3-sulfonic acid, 2,8-dihydroxynaphthalene-6-sulfonic acid, 1,8- dihydroxy-naphthalene-8-sulfonic acid, l,8aminonaphthol-5-sulfonic acid, 2,7-dihydroxy-3,6- disulfonic acid, 1,8-benzolyl-aminonaphthol-2-sulfonic acid, l,8-dihydroxynaphthalene-6-sulfonic acid, 2- hydroxy-3-naphthonic-acid-N,N-bis-B- hydroxyethylamide, 8-hydroxy-2-naphthonic-acidhydroxy-ethylamide, 1-(N'carboethoxymethylamino)- 8-naphthol-4-sulfonic acid, 5-(para-nitro)-benzamidelnaphthol, l-hydroxynaphthyl-7-phenylguanidine, 2- hydroxynaphthyl-S-biguanidine, l-naphthol-3-(N-B- hydroxyethyl)-sulfonamide, l-naphthol-3-(N-omethoxyphenyl)-sulfonamide, bis-[5hydroxy-7- sulfonaphthyl(2) ]-amine, and N,N-bis-[ l -hydroxy-3- sulfonaphthyl(6)]-thiourea.

Active methylene group-containing compounds such as l-phenyl-3-methyl-pyrazolone (5), acetoacetic acid anilide, l-phenyl-3-carboxypyrazolone, acetoacetic acid cyclohexylamide, acetoacetic acid benzylamide, cyanoacetoanilide, cyanoacetomorpholine, l (3 sulfonamide)-phenyl-3-methylpyrazolone-5, and H4- carboxy-ethylphenyl)-3-dodecyl-pyrazolone-5.

These couplers may be used singly, or mixtures of two or more of these compounds may be used.

Non-volatile or difficulty volatile, organic or inorganic acids are generally used as the acidic stabilizer (precoupling inhibitor) to be contained in the diazotype photosensitive material to be used in this invention. As such non-volatile or difficulty volatile acid there are mentioned, for example, citric acid, tartaric acid, oxalic acid, maleic acid, malic acid, succinic acid, sulfamic acid, boric acid, phosphoric acid, etc.

In this invention, such composition constituting the photosensitive layer of the diazotype photosensitive material to be used in this invention may further comprise an extender for improving the bondability of the composition to the substrate, the coating uniformity and water resistance. It is also possible to incorporate into such photosensitive composition additives orginarily used in the art, such as development promotors and coloring materials.

As the extender there may be employed, for example, dextrin, polyvinyl alcohol, gum arabic, colloidal silica, and polyvinyl borate emulsion. As the development 2,5dimethyl-4- 2-methyl-5-isopropyl-4- monomethyl ether,

promotor there may be used, for example, glycerine,

ethyleneglycol and other polyhydric alcohols. ln general, coloring materials are used for the purpose of indicating the surface to be exposed to light and increasing the whiteness of the background. As such coloring material there may be preferably used blue dyes such as Methylene Blue, Patent Blue, etc. Water and organic solvents such as alcohols, e.g., methanol and ethanol, ketones, e.g., acetones and methylethylketone, aro- 4-morpholine-.

matic hydrocarbons, e.g., toluene and xylene, and esters, e.g., ethyl acetate and butyl acetate are used for dissolving the above ingredients of the photosensitive composition constituting the photosensitive layer.

Two-component diazotype photosensitive compositions suitable for attaining the objects of this invention generally contain ingredients at ratios illustrated below, through the scope of this invention is not at all limited by such illustration:

Diazonium salt 0,l 4 7.- by weight, preferably 0.7 2 7: by weight Coupler 0.5 5 7c by weight, preferably 2 4 7r by weight Acidic stabilizer 0.1 5 k by weight, preferably 1.5 3 7r by weight Coloring material 0 0.025 by weight. preferably 0.0] 0.02 71 by weight Development promotor 0 l by weight, preferably 3 8 by weight Extender 0 5 by weight, preferably 3 5 by weight Solvent balance The above photosensitive composition is coated on a substrate such as paper, plastic film, woven fabric, nonwoven fabric or metal foil, whereby a two-component diazotype copying material is formed.

In accordance with this invention, a two-component diazotype photosensitive material having a photosensitive layer formed by application of the abovementioned two-component diazotype photosensitive composition is exposed image-wise to light emitted from a known light source used in the diazotype reproduction, such as from a fluorescent lamp, tungsten lamp, mercury lamp, arc lamp, xenon lamp, sun-light, etc. through an original having opaque image areas and transparent or semi-transparent non-image areas; whereby a pattern consisting of a latent image composed of the undecomposed diazonium salt and a background is formed on the photosensitive layer. The above operation can be accomplished by means known in the art.

According to the process of this invention, an activating liquor composed of a solution or dispersion of an alkali metal or alkaline earth metal salt of a carboxylic acid is applied to the photosensitive layer having a latent image consisting of the undecomposed diazonium salt.

Alkali metal and alkaline earth metal salts of organic compounds having at least one carboxyl group are used as far as they are soluble or dispersible in solvents to be used, and it does not matter whether they are volatile or not. In some cases, however, it is preferred that carboxylic acids are volatile and carboxylic acid salts are soluble in water. As the alkali metal for forming a salt with such carboxylic acid, there may be mentioned, for instance, potassium, sodium, lithium and rubidium, and use of sodium and potassium is especially preferred. As the alkaline earth metal there may be exemplified magnesium, calcium, barium, beryllium and strontium, and use of magnesium and calcium is especially preferred.

Examples of alkali metal and alkaline earth 'metal salts of carboxylic acids to be used in this invention are as follows:

a. Alkali metal and alkaline earth metal salts, e.g., so-

dium salts, potassium salts, lithium salts, Rochelle salts, magnesium salts, calcium salts and barium salts, of aliphatic monocarboxylic acids expressed by the following general formula RCOOMU,

wherein R is a saturated or unsaturated, straight, branched or cyclic mono-valent aliphatic groups which may have such substituents as halogen, hydroxyl, amino or sulfonic groups, M is an alkali metal or alkaline earth metal, and n is 1 or 2 indicating the valency of M;

such as alkali metal and alkaline earth metal salts of such aliphatic monocarboxylic acids as formic acid, acetic acid, propionic acid, acrylic acid, aconic'acid, acetoacetic acid, valdric acid, crotonic acid, butyric acid, undecanoic acid, butyric acid, capric acid, caprylic acid, chloroacetic acid, bromoacetic acid, trichloroacetic acid, chlorofumaric acid, cyclobutane-carboxylic acid, quinic acid, sulfoacetic acid, sorbic acid, tiglic acid. tetrolic acid, vinylacetic acid, pyruvic acid, methacrylic acid, levulinic acid, caproic acid, isovaleric acid, pelargonic acid, palmitic acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, tridecanoic acid, morganic acid, behenic acid, stearclic acid, glycolic acid, citric acid, tartaric acid, adipic acid, arabonic acid, alloxanic acid, saccharic acid, isovanillic acid, hydroxybutyric acid, glyceric acid, gluconic acid, diglycolic acid, citramanic acid, thioglycolic acid, desoxalic acid, lactic acid, racemic acid, mannonic acid, malic acid, leucic acid, glycine, alanine, leucine, serine, threonine, cysteine, lysine and arginine.

Sodium and potassium salts of formic acid and acetic acid are especially preferably among the abovementioned alkali metal or alkaline earth metal salts of carboxylic acids.

b. Alkali metal and alkaline earth metal salts, e.g., so-

dium salts, potassium salts, lithium salts, magnesium salts, calcium salts, and barium salts, of aliphatic polycarboxylic acids expressed by the following general formula wherein R is a saturated or unsaturated, straight, branched or cyclic poly-valent aliphatic group which may have such substituents as halogen, hydroxyl, amino or sulfonic groups, m is the valency of the aliphatic group, and M and n are as defined above;

such as alkali metal and alkaline earth metal salts of Sodium and potassium salts of oxalic acid and malonic acid are especially preferred among these alkali metal and alkaline earth metal salts of carboxylic acids.

c. Alkali metal and alkaline earth metal salts, e.g., so-

dium salts, potassium salts, lithium salts, magnesium salts, calcium salts and barium salts, of aromatic monoand poly-carboxylic acids expressed by the following general formula wherein Ar stands for a mono-valent or polyvalent aryl or aliphatic groups which may have such substituents as halogen, amino, hydroxyl, mercapto, alkyl, alkenyl, hydroxyalkyl, acyl and sulfonic groups, p is the valency of the Ar group, and M and n are defined above;

such as alkali metal and alkaline earth metal salts of such aromatic carboxylic acids as benzoic acid, phthalic acid, terephthalic acid, trimellitic acid. salicylic acid, acetophenone-carboxylic acid, anisic acid, aminobenzoic acid, aminocinnamic acid, propylbenzoic acid, hydroxyphthalic acid, hydroxyphenylacetic acid, cinnamic acid, chlorobenzoic acid, chlorophthalic acid, dimethoxyphthalic acid, sulfosalicylic acid, thiosalicylic acid, toluic acid, truxillic acid, tropic acid, naphthalic acid, vanillic acid, biphenyl-carboxylic acid, phenyl-acetic acid, phenylsuccinylacetic acid, phenyl-lactic acid, benzenetetracarboxylic acid, phenylbutyric acid, benzoylbenzoic acid, benzoylglucolic acid, benzoylacetic acid, homophthalic acid, mandelic acid, phenylalanine and tryosine.

Sodium and potassium salts of benzoic acid and salicylic acid are especially preferred among the above-mentioned alkali metal and alkaline earth metal salts of aromatic carboxylic acids.

d. Alkali metal and alkaline earth metal salts of heterocyclic monoand poly-carboxylic acids such as sodium, potassium, lithium, magnesium, calcium and barium salts of 2,4-dimethyl-3-furancarboxylic acid, thiophenecarboxylic acid, terpenylic acid, paraconic acid, furanacarboxylic acid, alginic acid, coumarinic acid, and pyridine-carboxylic acid.

In the activating liquor to be used in this invention, one or more of the above-mentioned carboxylic acid salts need not be completely dissolved, but a dispersion (or suspension) of such salt may also be used. Water is most preferred as a medium for dissolving such carboxylic acid salt, but it is also possible to use aqueous mixtures of water-miscible organic solvents such as polyhydric alcohols, e.g., methanol, ethanol and propanol, ketones, e.g., acetone and methylethylketone, and polyhydric alcohols, e.g., ethylene glycol and glyceral. Still in addition, organic solvents capable of dispersing therein carboxylic acid salts can be used in this invention. As such solvent there may be exemplified alcohols such as methanol, ethanol and propanol, ketones such as acetone and methylethylketone, aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, ethers such as butyl ether, propyl ether, dioxane and trioxane, and halogenated hydrocarbons such as chloroform and carbon tetrachloride.

The activating liquor to be used in this invention contains the alkali metal or alkaline earth metal salt of a carboxylic acid at a concentration generally ranging from 5 to 60 percent by weight, preferably 10 to 40 percent by weight, based on the amount of the activat above-mentioned range. Since the activating liquor is applied to the two-component diazotype photosensitive material, it is important that the activating liquor should not contain a coupler. In addition to the abovementioned carboxylic acid salt, the activating liquor may further comprise small amounts of assistants as optional components. Examples of such assistants include dye-insolubilizing agents such as disclosed in Japanese Patent Publication No. 45-27680/70, e.g., quaternary ammonium compounds and amines; penetrants such as monoand poly-hydric alcohols, or non-ionic surface active agents; and extenders such as dextrin, starch, and polyvinyl alcohol. In order to improve the visual whiteness of the background, it is possible to incorporate in the activating liquor a whitening agent such as fluorescent dyes and blue dyes.

A typical instance of the composition of an activating liquor to be used preferably in this invention is as follows:

Alkali metal or alkaline earth metal carboxylate Penetrant Dye-insolubilizing agent Extender Whitening agent Solvent In accordance with this invention, a small amount of the activating liquor is applied to the exposed twocomponent diazotype photosensitive material, and it is preferred that the activating liquor is applied uniformly to the light-exposed photosensitive layer. In this invention, it is sufficient that the amount of the activating agent is such that the photosensitive layer is wetted with the activating liquor, and it is generally unnecessary to drench the photosensitive layer with the activating liquor. Of course, it is possible to apply a considerable amount of the activating liquor to the photosensitive layer, but any particular advantage is not attained by application of the activating liquor in a great amount. Further, when a diazonium salt or coupler contained in the photosensitive layer is readily soluble in water, use of a great amount of the activating liquor results frequently in such defects as flow and blot of a copied image.

The amount applied of the activating liquor liquor varies considerably depending on the kind of the carboxylic acid salt contained in the activating liquor, but generally speaking, it is preferred that the activating agent is applied in an amount of l to g, especially 4 to 10 g, per square meter of the photosensitive layer.

Application of the activating liquor can be accomplished by means known per se, for instance, roller coating, spraying and other liquid-applying methods. For instance, when the application of the activating liquid on the two-component diazotype photosensitive layer is carried out by employing a roll, the abovementioned amount of the activating liquor is at first applied on the coating roll and then a thin layer of the activating liquor on the coating roll is transferred onto the photosensitive layer. As such coating roll, there may be employed, for instance, a smooth metal roll, a mesh roll, a rubber roll, a sponge roll and the like.

In the two-component diazotype photosensitive material which has been exposed to light and on which a small amount of the activating liquor has been applied, a latent image formed on the photosensitive layer can be developed into a visible image without any particular heating (namely allowing it to stand still at temperatures approximating room temperature). In such case, however, it takes time to develop the latent image into a visible image. Therefore, in general, heating is used to develop the latent image consisting of the undecomposed diazonium salt and coupler and obtain a copy sheet in the dry state. The heating temperature varies greatly depending on the kind of the activating liquor or combination of the diazonium salt and coupler. In general, however, it is desired that the heating is effected at 50 to 250C, preferably 60 to 200C, especially to C. To conduct the development at such elevated temperatures is advantageous in that de velopment is accomplished instantaneously and a dry copy sheet is obtained. In case the activating liquor is free of water, it is important that the heating is effected with use of steam or the photosensitive layer is wetted with water by some means prior to heating.

The heating of the photosensitive material can be conducted with ease by optional heating means, for instance, a heating roll, infrared irradiation, hot air, heated steam or the like.

Reasons why the alkali metal or alkaline earth metal carboxylate promotes development in the twocomponent diazotype photosensitive material in this invention have not been completely elucidated. However, in view of the fact that the alkali metal or alkaline earth metal carboxylate is a neutral salt and is stable at high temperatures, it is readily presumed that the car boxylate or its thermal decomposition product may neutralize the acidic stabilizer in the two-component diazotype photosensitive composition and initiate coupling of the diazonium salt with the coupler. We construe that the reason why the alkali metal or alkaline earth metal carboxylate enables coupling of the diazonium salt with the coupler at relatively low temperatures is not that the carboxylate acts on the acidic stabilizer but that the carboxylate activates the diazonium salt by synergetic activity with the heat thereby initiating initiate coupling of the diazonium salt with the coupler regardless of the presence of the acidic stabilizer.

In the process of this invention, since the ingredient of the activating liquor is a salt stable. even at high temperatures, one obvious advantage is that development can be accomplished easily without formation of a nasty or irritative decomposition gas. Further, since the ingredient of the activating liquor to be applied on the two-component diazotype photosensitive material is a non-volatile salt, it is sufficient that the activating liquor is applied only in a very small amount. Accordingly, the process of this invention is advantageous also from the economical viewpoint, and any special opera tion need not be effected to dry a copy sheet. Still further, even when the ingredient of the activating liquor applied to the two-component diazotype photosensitive material is left on the photosensitive layer, since the alkali metal or alkaline earth metal carboxylate is a new tral salt which is stable of itself, it exhibits no tendency of discoloring the coupler remaining in the photosensitive layer unlike conventional free organic amines or inorganic alkalis. In fact, copy sheets obtained accord ing to the process of this invention, as copy sheets obtained by the dry development method using a gaseous mixture of ammonia and steam, are characterized in that distinction of the non-exposed areas is very high (whiteness of the background is excellent) and discol oration hardly occurs even when copy sheets are stored for a long period of time.

As compared with the dry developing method, the process of this invention is generally advantageous in that copy sheets excellent in the image density and water resistance can be obtained. For instance, in the case of a combination of dihydroxynaphthalene sulfonic acid and a diazonium salt, which is most commonly used in two-component diazotype photosensitive copying papers for the dry development, copied images are relatively faintly blue and poor in water resistance when the development is conducted by the dry development method using a gaseous mixture of ammonia and vapor. In contrast, if the activating liquor of this invention, for instance, an aqueous solution of sodium acetate is applied to such photosensitive papers, images of a dense violet color excellent in water resistance can be obtained.

The process of this invention can be effectively applied not only to ordinary diazotype reproduction processes but also to multi-color reproduction processes such as disclosed in German Patent Application Laid- Open Specification No. 2,007,690.

This invention will now be detailed by reference to Examples, from which effects and advantages of this invention will readily be understood.

EXAMPLE 1 A composition of the following recipe was coated on a substrate paper for a photosensitive copying sheet by means of an ordinary coating device such as an air knife coater, and dried to form a two-component diazo type photosensitive paper for heat development:

4-Diazo-N,N-dimethylaniline g chloride-rfiZnCl Diethyleneglycol 60 g Citric acid 40 g Sodium 2,7-dihydroxynaphthaleneg 3,6-disulfonate Zinc chloride 50 g Thiourea 50 g Patent Pure Blue 0.1 g Water balance Total 1 liter The so formed photosensitive copying sheet was overlapped with an original sheet having an image thereon, and the assembly was exposed to light emitted from a mercury lamp disposed above the assembly thereby to form a latent image of the diazonium salt. Then, an activating liquor of the following recipe was applied uniformly onto the surface of the copying sheet in an amount of about 8 g per square meter of the copying sheet surface by means of a coating roll:

Sodium acetate 150 g Diethyleneglycol 50 g Water balance Total 1 liter Then, the activating liquor-applied copying sheet was allowed to have an instantaneous contact with a heating roll of the heat transfer type maintained at about C. to effect the development. A copy sheet having an image of a clear blue was obtained.

Example 2 A composition of the following recipe was coated on a substrate paper for a photosensitive copying sheet by means of an ordinary coating device such as air knife coater, and dried to form a two-component diazotype photosensitive paper for heat development:

4-Diazo-N-ethyl-N-hydroxyethylaniline 15 g zfiZnCl, 50 g Glycerine 50 g Tartaric acid 30 g Sodium 2,3-dihydroxy6-sulfonate 40 g Zinc chloride 50 g Thiourea 30 g Patent Blue 0.1 g Water balance Total l liter Lithium acetate [50 g Ethyleneglycol 50 g Dye'insolubilizing agent of polyamine type 10 g (Morin Fix PA Conc manufactured by Morin Chemical Industries, Inc.)

Water balance Total 1 liter The activating liquor-applied sheet was instantaneously heated at about C. by means of infrared irradiation. A copy sheet having an image of a clear blue color was obtained.

Example 3 A composition of the following recipe was coated on a substrate paper in the same manner as in Example 1 and dried to obtain a diazotype photosensitive copying sheet for heat development and black coloration:

4'Diazo-N,N-diamethylaniline chloride kZnCl Diethylene glycol Tartaric acid Sodium 2,7-dihydroxynaplithalene- 3,6disulfonate Resorcinal Acetoacetoanilide Zinc chloride Thiourea Sodium l,3.G-naphthalene-trisulfonate Patent Blue Water Total The so formed copying sheet was overlapped with an original sheet having an image thereon, and the assembly was exposed to light emitted from a mercury lamp disposed above the assembly thereby to form a latent image of the diazonium salt thereon. Then, an activating liquor of the following recipe was applied on the copying sheet by spray coating in an amount of about 5 g per square meter of the copying sheet surface:

Sodium formate 80 g Sodium tartrate 100 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at 80 90C. A copying sheet having a black image was thus obtained.

Example 4 A composition of the following recipe was applied on a substrate for a copying sheet in the same manner as in Example 1 and dried to obtain a two-component diazotype copying sheet for heat development and red coloration:

4-Diazo-N-methyl-Nhydroxyethylaniline 15 g chloride' /zZnCl Diethyleneglycol 75 g a-Resorcylic acid ethanolamine 8 g Citric acid 40 g Zinc chloride 50 g Thiourea 25 g Patent Blue 0.1 g Water balance Total l liter The so formed copying sheet was exposed to light in the same manner as in Example 1 to form a latent image of .the diazonium salt, and an activating liquor of the following recipe was coated thereon by a coating roll in an amount of about 8 g per square meter of the copying sheet surface:

Potassium formate 50 g Sodium oleate 100 g Water balance Total l liter The activating liquor-applied copying sheet was instantaneously contacted with heated steam (maintained at about 100C.) thereby to obtain a copy sheet having a copied image of a red color.

Example 5 A composition of the following recipe was coated on a substrate paper for a copying sheet in the same manner as in Example 1 and dried to obtain a twocomponent diazotype phososensitive copying sheet for heat development:

4-Diazo-2.5-dibutoxy-N-phenylg morpholineZnCl,

Tartaric acid 30 g Dielhylene glycol 50 g fl-Hydroxynaphthoic acid aminoethylamine 7 g Zinc chloride 25 g Thiourea 25 g Patent Blue 0.1 g

Water balance Total 1 liter Sodium potassium tartrate 150 g V Potassium acetate 50 g 5 wa r balance Total 1 liter Then, the activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at about 100C. to obtain a copy sheet having a copied image of a blue color.

Example 6 A solution of the following recipe was coated on a 5 semi-transparent tracing paper and dried to obtain a two-component diazotype copying sheet for heat development and for formation of a second original:

4-Diazo-N-ethyl-N-hydroxyethylaniline g chloride VzZnCl Tartaric acid 40 g Ethyleneglycol 50 g Resorcinal 100 g Phloroglucinol 2 g Zinc chloride 40 g Boric acid 10 g 25 Water balance Total 1 liter The so formed photosensitive copying sheet was overlapped with an original sheet having an image and the assembly was exposed to light emitted from a mercury lamp disposed above the assembly to form a latent image of the diazonium salt. Then, an activating liquor of the following recipe was applied to the copying sheet in an amount of about 5 g per square meter of the copying sheet surface by means of a coating roll:

Sodium monochloroacetate 100 g Sodium formate 50 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at 1 10C. to obtain a copy sheet having a brown-colored image which could be used as a second original.

Example 7 A solution of the following recipe was coated on a substrate paper for a photosensitive copying sheet according to a customary coating method using an air knofe coater and dried at a relatively low temperature (80- 90C.) to obtain a two-component diazotype photosensitive sheet for heat development:

4-Diazo-N,N-dimethylaniline%ZnCl Tartaric acid Sodium 2.3-dihydroxynaphthaleneo-sulfonate Urea Thiourea Saponin Methylene Blue Water Total The so formed copying sheet was overlapped with a semi-transparent original sheet having an image thereon and the assembly was exposed to light emitted from a mercury lamp disposed above the assembly to form a latent image of the diazonium salt on the copying sheet. An activating liquor of the following recipe was applied on the copying sheet by means of a coating roll in an amount of about g per square meter of the copying sheet surface:

Sodium benzoate 150 g Polyvinyl alcohol 5 g Diethyleneglycol 50 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at about 100C. thereby to obtain a copy sheet having a blue-colored image.

Example 8 A composition of the following recipe was coated on a polyester film by means of a rod coater and dried by hot air maintained at about 100C. to obtain a twocomponent diazotype photosensitive film for heat development:

4-Diazo-2,5-dibutoxy-N- g phenylmorpholinerZnCl Tartaric acid 8 g B Hydroxynaphthoic acid ethanolamine 8 g Butylated urea resin 4 g Oil Blue 0.2 g Methanol balance Total 1 liter The so formed photosensitive copying sheet overlapped with an original sheet having an image thereon, and the assembly was exposed to light emitted from a mercury lamp disposed above the assembly to form a latent image of the diazonium salt on the copying sheet. An activating liquor of the following recipe was applied to the copying sheet by means of a coating roll in an amount of about 3 g per square meter of the copying sheet surface:

Sodium formate l00 g Sodium oleate 50 g Methanol 80 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with heated steam maintained at about 100C. thereby to obtain a copy sheet having a blue-colored image.

Example 9 A solution of the following recipe was coated by means of an air knife coater on a substrate paper which had been treated in advance with a percent solution of a butadiene-methyl methacrylate copolymer resin emulsion, and dried to obtain a two-component diazotype photosensitive copying sheet for heat development and multi-color reproduction:

4-Diazo-N,N-dimethylaniline chloride-AZnCl Diethylcneglycol 4 Tartaric acid Sodium 2,7-dihydroxynaphthalene- 3,6-disulfonate Zinc chloride 10 Thiourea 40 Patent Blue 0 -Contlnued balance 1 liter Water Total Red-Color-Forming Liquor l-Phenyl-3-methylpyraz0lone(5) 20 g Polyvinyl acetate resin emulsion (50 7d 5 g Thiourea 5 g Methanol balance Total ml Yellow-Color-Forming Liquor Resorcinol 50 g Thiourea 4 g Methanol balance Total 1 liter The above assembly of the copying sheet and original was heated and exposed to light by means of a light source installed with a mercury lamp and an infrared irradiator and disposed above the assembly. Thus, a latent image of the diazonium salt was formed on the copying sheet and at the same time the thermovolatile couplers were transferred to the copying sheet at parts corresponding with the treated portions of the original sheet. An activating liquor of the following recipe was applied to the copying sheet in an amount of about 7 g per square meter of the copying sheet surface:

Sodium trichloroacetate I50 g Dextrin 20 g Dye-insolubilizing agent 10 g (Morin Fix Conc 2 R manufactured by Morin Chemical Industry, lnc.)

Water balance Total l liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at about C. to obtain a three-color copy sheet in which the part corresponding with the portion of the original treated with the red-color-forming liquor was colored red, the part corresponding with the portion of the original treated with the yellow-color-forming liquor was colored yellow and the part corresponding with the untreated portion of the original was colored blue.

Example 10 A solution of the following recipe was coated on a substrate paper in the same manner as in Example 1 and dried to obtain a photosensitive copying sheet for heat development and for twocolor reproduction:

4-Diazo-N-methyl-N-hydroxyethylaniline 12 g chloride kZnCl Z-Diazo-l-naphthol-5-sulfonic acid 30 g Tartaric acid 80 g Diethyleneglycol 40 g -Continued EXAMPLE 12 Zinc chloride 50 g Thiourea 25 g A solution f the f ll win was Sodium l,3,6naphthalene-trisulfonate 30g i O o g reclpe Coated on a water balance substrate paper in the same manner as m Example 1 1: Total 1 liter 5 4-Diazo-2.5-dibutoxy-N- g phenylmorpholine' fzZnCl Tartaric acid 30 g Diethyleneglycol 50 g B-Hydroxynaphthoic acid aminoethylamine '7 g Zinc chloride 25 g Thiourea 25 g Patent Blue 0.1 g Water balance Total 1 liter Potassium acetate 50 g Sodium salicylate 80 g Polyvinyl alcohol 10 g Glycerine 10 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at The so formed two-component diazotype photosensitive copying sheet was overlapped with an original sheet and the assembly was exposed to light in the same manner as in Example 11 thereby to form a latent image of the diazonium salt on the copying sheet. Then, an activating liquor of the following recipe was applied on the copying sheet by means of a coating roll in an amount of about 6 g per square meter of the copying sheet surface:

about 110C. to effect the development. A two-color copy sheet in which the part corresponding with the image portion drawn with the drafting ink was colored blue and the part corresponding with the image portion drawn with the pencil colored redwas thus obtained.

Example 1 l A solution of the following recipe was coated on an ordinary substrate paper for a copying sheet by means of an air knife coater and dried to obtain a two- 3 5 component diazotype photosensitive copying sheet for heat development:

Magnesium tartrate 150 g Calcium acetate 50 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at about 100C. thereby obtaining a copy sheet having a blue-colored image.

EXAMPLE 13 A solution of the following recipe was coated on a substrate paper for a copying sheet by a customary coating method employing an air knife coater and dried izggg z' 15 g 40 at a relatively low temperature (80 90C.) to obtain Glycerine 50 g a two-com onent diazot e hotosensitive co in Tartaric acid 30 g yp p py g Sodium 2,3-dihyclroxy-6-sulfonate 40 g sheetfor heat development: Zinc chloride 50 s Thiourea 30 g Patent Blue 0.1 g 4) -N t l A water balance franlzfizg 181:; dime hy aniline ZnCl, 1; 5 Tom] 1 met Sodium 2,S-dihydroxynaphthalene-6-sulfonate 40 g Trichloroacetic acid g The so formed copying sheet was overlapped with an g fifg 52 8 original sheet having an image thereon, and the assemsaponin g bly was exposed to light emitted from a mercury lamp, 50 Methylene Blue 0.1 g

l Water. balance a fluorescent lamp or other llght source disposed above Total 1 met the assembly to form a latent image of the diazonium salt on the copying sheet. Then, an activating liquor of the following recipe was applied on the copying sheet The so formed photosensitive copying sheet was overlapped with a semi-transparent original sheet having an y means Ufa Coating in an amount of about 3 8 P 55 image thereon, and the assembly was exposed to light square meter of the copying sheet surface:

The activating liquor-applied copying sheet was instantaneously heated at about C. by infrared irradiation thereby to obtain a copy sheet having an image of a clear blue color.

emitted from a mercury lamp disposed above the assembly to form a latent image of the diazonium salt. An activating liquor of the following recipe was coated on the copying sheet by means of a coating roll in an 60 amount of about 5 g per square meter of the copying sheet surface:

Magnesium benzoate g Polyvinyl alcohol 5 g Diethylene glycol 50 g Water balance Total 1 liter The activating liquor-applied copying sheet was instantaneously contacted with a heating roll maintained at about 100C. thereby to form a copy sheet having a blue-colored image.

In order to illustrate excellent effects attained by conducting the heat development with use of an activating liquor containing an alkali metal or alkaline earth metal carboxylate according to the process of this invention, the following experiments were carried out.

Experimental Procedures Two-component diazotype photosensitive copying sheets were prepared by coating on substrate papers by means of an air knife coater a photosensitive composition of the following recipe that is most customarily used in the art and drying it:

4-Diazo-N-ethyl-N-hydroxyethylaniline Glycerine 50 g Tartaric acid 30 g Sodium 2,3-dihydroxy-6sulfonate 40 g Zinc chloride 50 g Thiourea 25 g Saponin 0.3 g Patent Blue 0.l g Water balance Total I liter.

Each of the so formed photosensitive copying sheets was overlapped with an original having an image thereon and exposed to light, following which the development was carried out by either of the following development methods. I. Development Process of This Invention An activating liquor of the following recipe was coated on the above light-exposed copying sheet by means of a coating roll in an amount of about 8 g per square meter of the copying sheet surface:

Sodium acetate I50 g Diethyleneglycol 50 g Dextrin g Dye-insolubilizing agent g (Morin Fix PA Conc manufactured by Morin Chemical Industry, Inc.)

Water balance Total 1 liter The so treated copying sheet was instantaneously contacted with a heating roll maintained at about 120C. to effect the development. 2. Development Process Using Gaseous Mixture of Ammonia and Steam The above light-exposed copying sheet was contacted with a gaseous mixture of ammonia and steam according to a customary method to effect the development. 3. Development Process Using Nitrogen-Containing Organic Base In accordance with the teachings of Japanese Patent Publication No. 39-8149/64, a liquid developer of the following recipe was coated on the above light-exposed copying sheet by means of a coating roll in an amount of about 10 g per square meter of the copying sheet surface:

Triethanolamine I0 100 The so treated copying sheet was instantaneously contacted with a heating roll maintained at about C. to effect the development. 4. Development Process Using Aqueous Solution of Alkali In accordance with the teachings of Japanese Patent Publication No. 43-13815/68, an aqueous solution of the following recipe was coated on the above lightexposed copying sheet by means of a coating roll in an amount of about 7 g per squre meter of the copying sheet surface:

Potassium carbonate 5 g Water balance Total I00 ml With respect to each development process, the development efficiency was evaluated by the following procedures.

METHODS OF MEASUREMENT OF DEVELOPMENT EFFICIENCY a. Image Density With respect to the copy sheets obtained by the above development processes, the Y value of the unexposed area of the copied image was measured by means of a color-difference meter of type No. 4 manufactured by Nippon Denshoku Co., Ltd., and the image density was expressed in terms of the value of log Y). b. Coloring Rate The coloring state was visually evaluated with respect to each of the above development processes. c. Discoloration of Copied Image (Photoresistance) Unexposed and completely exposed portions of the sample copying sheet were developed by either of the above development processes, and then exposed to light emitted from a mercury lamp of 800 W disposed 30 cm apart from the copy sheet surface for 3 hours. L, a and b values according to UCS chromatocity were measured by means of a color difference meter (manufactured by Nippon Denshoku) and the discoloration was expressed in terms of the color difference of the so treated copying sheet (AE) from the untreated sample copying sheet calculated by the following formula:

d. Water Resistance of Copied Image An image of the unexposed portion developed by either of the above development processes was dipped in flowing water maintained at 18C. for 5 minutes, and then dried. The dye concentration log Y) was measured with respect to the so treated copy and the untreated copy by means of a color difference meter of ND-4 type (manufactured by Nippon Denshoku), and the dye residual ratio was calculated by the following equation:

Dye residual ratio Remaining dye concentration of treated copy/Dye concentration to untreated copy e. Flow of Image at Development With respect to each of the above development processes, the state of flow of the image was visually examined.

Results of these tests are shown in Table given below.

From the test results shown in the Table, it is seen that the development process of this invention is not substantially different from the conventional dry development method using a gaseous mixture of ammonia and water with respect to the development efficiency and the process of this invention is superior to the said conventional dry development method with respect to the water resistance of the copied image. It is also seen that the process of this invention is superior to the conventional method employing a nitrogen-containing organic base in that the concentration of the colored image is higher in the process of this invention and such fatal effects of the conventional method as contamination and discoloration of the copied image are prominently overcome in the process of this invention. Further, in the method employing an aqueous alkali slution it can be seen that, the flow of the image was extreme with the copy lacking accuracy. Clearly, there is no comparison with such process and the process of the instant invention.

polycarboxylic acids, heterocyclic monocarboxylic acids and heterocyclic polycarboxylic acids.

3. A process set forth in claim 2, wherein the aliphatic monocarboxylic acid is one selected from the group consisting of formic acid, acetic acid, propionic acid, acrylic acid, aconic acid, acetoacetic acid, valerianic acid, crotonic acid, butyric acid, undecanoic acid, enanthic acid, capric acid, caprylic acid, chloro-acetic acid, bromacetic acid, trichloracetic acid, chlorofumaric acid, cyclobutane-carboxylic acid, quinic acid, sulfoacetic acid, sorbic acid, tiglic acid, tetrolic acid, vinylacetic acid, pyruvic acid, methacrylic acid, levulimic acid, caproic acid, isovaleric acid, pelargonic acid, palmitic acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, tridecanoic acid, margaric acid, behenic acid, stearolic acid, glycolic acid, citric acid, tartaric acid, aconitic acid, adipic acid, arabonic acid, alloxanic acid,

Table Test Items Development Processes Process of this Process Using Process Using Process Using invention Gaseous Mixture Nitrogen Aqueous Solution of Ammonia and Containing of Alkali Water Organic Base Colored image Density {-log Y) 1.1079 1.1872 0.7852 0.7167 Qoloring Rate almost simultaneously instanhigh temperature revery low with heating taneously quired; rate was low at 150C. Discoloration of Copy (AE) tghotoresistance) I image portion 6.8 7.8 18.4 flow of image was extreme and image: nonimage portion 7.2 5.2 20.1 lacked accuracy Water Resistance of Image 1%) 89.2 83.5 87.3 Flow of image at Development hardly observed considerably observed What we claim is:

1. In a process for wet developing two-component diazotype photosensitive materials comprising exposing image-wise to actinic light a photosensitive material having a two-component diazotype photosensitive layer consisting essentially of a photosensitive diazonium salt, a coupler capable of coupling with the diazonium salt and an acidic stabilizer, and developing said photosensitive material by applying a small amount of an activating liquid to the photosensitive layer of the exposed photosensitive material, the improvement characterized in that the activating liquid consists essentially of:

a. an alkali metal carboxylate and/or an alkaline earth metal carboxylate 5-60% by weight;

b. a penetrant 020% by weight;

c. a dye-insolubility agent 0-15% by weight;

d. an extender 0-20% by weight;

e. a whitening agent agent 0-0.5% by weight; and

f. water to .100 percent of the activating liquid; with development carried out by heating the activating liquid applied to the photosensitive material at a temperature in the range of from 70 to 120C.

2. A process set forth in claim 1, wherein the carboxylic acid is one selected from the group consisting of aliphatic monocarboxylic acids, aliphatic polycarboxylic acids, aromatic monocarboxylicacids, aromatic saccharic acid, isovanillic acid, hydroxybutyric acid, glyceric acid, gluconic acid, diglycolic acid, citramanic acid, thioglycolic acid, desoxalic acid, lactic acid, racenic acid, mannonic acid, malic acid, leucic acid, glycine, alanine, leucine, serine, threonine, cysteine, methionine, lysine and arginine.

4. A process set forth in claim 2, wherein the aliphatic polycarboxylic acid is one selected from the group consisting of malonic acid, acetonedicarboxylic acid, citraconic acid, oxalic acid, acrylmalonic acid, isocamphoronic acid, ethylmalonic acid, glutaric acid, succinic acid, camphoric acid, sebacic acid, pimelic acid, brassylie acid, maleic acid, muconic acid, mesaconic acid, adipic acid, axelaic acid, suberic acid, aspartic acid and glutamic acid.

5. A process set forth in claim 2, wherein the aro matic monoor poly-carboxylic acid is one selected from the group consisting of benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, salicylic acid, acetophenone-carboxylic acid, anisic acid, aminobenzoic acid, aminocinnamic acid, propylbenzoic acid, bydroxy-phthalic acid, hydroxyphenylacetic acid, cinnamic acid, chlorobenzoic acid, chlorophthalic acid, dimethoxyphthalic acid, sulfosalicylic acid, thiosalicylic acid, toluic acid, truxillic acid, tropic acid, naphthalic acid, vanillic acid, biphenyl-carboxylic acid, phenyl-acetic acid, phenylsuccinylacetic acid, phenyllactic acid, benzene tetracarboxylicl acid, phenylbutyric acid, benzoylbenzoic acid, benzoylglucolic acid, ben- 23 24 zoyiacetic acid, homophthalic acid, mandelic acid, furancarboxylic acid, thiophenecarboxylic acid, terpephenylalanme and tyrosme' nylic acid, paraconic acid, furancarboxylic acid, alginic 6. A process set forth in claim 2, wherein the heterocyclic monoor poly-carboxylic acid is one selected from the group consisting of 2,4-dimethyl-3- 5 acid, coumarinic acid and pyridine-carboxylic acid.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3320,996 Dated June 28, 1974 Inrentofle) Nihyakumen, et el It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, subparagraph "e", delete "agent" in the second instance.

Claim 3, line 6, delete "chloro-acetic", insert chloroacetic-- Claim 3, line 7, delete "bromacetic", insert bromoacetic Claim 3, line 7, delete "trichloracetic", insert trichloroacetic Claim 4, line 8, delete "axelaic", insert azelaic Signed and sealed this 8th day of October 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM PO'1O5OHO'69) uscoMM-oc wan-ps9 U.S. GOVERNMENT PRINTING OFFICE 19, O-3"334, 

2. A process set forth in claim 1, wherein the carboxylic acid is one selected from the group consisting of aliphatic monocarboxylic acids, aliphatic polycarboxylic acids, aromatic monocarboxylic acids, aromatic polycarboxylic acids, heterocyclic monocarboxylic acids and heterocyclic polycarboxylic acids.
 3. A process set forth in claim 2, wherein the aliphatic monocarboxylic acid is one selected from the group consisting of formic acid, acetic acid, propionic acid, acrylic acid, aconic acid, acetoacetic acid, valerianic acid, crotonic acid, butyric acid, undecanoic acid, enanthic acid, capric acid, caprylic acid, chloro-acetic acid, bromacetic acid, trichloracetic acid, chlorofumaric acid, cyclobutane-carboxylic acid, quinic acid, sulfoacetic acid, sorbic acid, tiglic acid, tetrolic acid, vinylacetic acid, pyruvic acid, methacrylic acid, levulimic acid, caproic acid, isovaleric acid, pelargonic acid, palmitic acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, tridecanoic acid, margaric acid, behenic acid, stearolic acid, glycolic acid, citric acid, tartaric acid, aconitic acid, adipic acid, arabonic acid, alloxanic acid, saccharic acid, isovanillic acid, hydroxybutyric acid, glyceric acid, gluconic acid, diglycolic acid, citramanic acid, thioglycolic acid, desoxalic acid, lactic acid, racenic acid, mannonic acid, malic acid, leucic acid, glycine, alanine, leucine, serine, threonine, cysteine, methionine, lysine and arginine.
 4. A process set forth in claim 2, wherein the aliphatic polycarboxylic acid is one selected from the group consisting of malonic acid, acetone-dicarboxylic acid, citraconic acid, oxalic acid, acrylmalonic acid, isocamphoronic acid, ethylmalonic acid, glutaric acid, succinic acid, camphoric acid, sebacic acid, pimelic acid, brassylic acid, maleic acid, muconic acid, mesaconic acid, adipic acid, axelaic acid, suberic acid, aspartic acid and glutamic acid.
 5. A process set forth in claim 2, wherein the aromatic mono- or poly-carboxylic acid is one selected from the group consisting of benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, salicylic acid, acetophenone-carboxylic acid, anisic acid, aminobenzoic acid, aminocinnamic acid, propylbenzoic acid, hydroxy-phthalic acid, hydroxyphenylacetic acid, cinnamic acid, chlorobenzoic acid, chlorophthalic acid, dimethoxyphthalic acid, sulfosalicylic acid, thiosalicylic acid, toluic acid, truxillic acid, tropic acid, naphthalic acid, vanillic acid, biphenyl-carboxylic acid, phenyl-acetic acid, phenylsuccinylaceTic acid, phenyl-lactic acid, benzene tetracarboxylic acid, phenylbutyric acid, benzoylbenzoic acid, benzoylglucolic acid, benzoylacetic acid, homophthalic acid, mandelic acid, phenylalanine and tyrosine.
 6. A process set forth in claim 2, wherein the heterocyclic mono- or poly-carboxylic acid is one selected from the group consisting of 2,4-dimethyl-3-furancarboxylic acid, thiophenecarboxylic acid, terpenylic acid, paraconic acid, furancarboxylic acid, alginic acid, coumarinic acid and pyridine-carboxylic acid. 